/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: XMLCharacterRecognizer.java,v 1.2.4.1 2005/09/15 08:16:01 suresh_emailid Exp $
 */
package com.sun.org.apache.xml.internal.utils;

/**
 * Class used to verify whether the specified <var>ch</var>
 * conforms to the XML 1.0 definition of whitespace.
 * @xsl.usage internal
 */
public class XMLCharacterRecognizer {

    /**
     * Returns whether the specified <var>ch</var> conforms to the XML 1.0 definition
     * of whitespace.  Refer to <A href="http://www.w3.org/TR/1998/REC-xml-19980210#NT-S">
     * the definition of <CODE>S</CODE></A> for details.
     * @param ch Character to check as XML whitespace.
     * @return =true if <var>ch</var> is XML whitespace; otherwise =false.
     */
    public static boolean isWhiteSpace(char ch) {
        return (ch == 0x20) || (ch == 0x09) || (ch == 0xD) || (ch == 0xA);
    }

    /**
     * Tell if the string is whitespace.
     *
     * @param ch Character array to check as XML whitespace.
     * @param start Start index of characters in the array
     * @param length Number of characters in the array
     * @return True if the characters in the array are
     * XML whitespace; otherwise, false.
     */
    public static boolean isWhiteSpace(char ch[], int start, int length) {

        int end = start + length;

        for (int s = start; s < end; s++) {
            if (!isWhiteSpace(ch[s]))
                return false;
        }

        return true;
    }

    /**
     * Tell if the string is whitespace.
     *
     * @param buf StringBuffer to check as XML whitespace.
     * @return True if characters in buffer are XML whitespace, false otherwise
     */
    public static boolean isWhiteSpace(StringBuffer buf) {

        int n = buf.length();

        for (int i = 0; i < n; i++) {
            if (!isWhiteSpace(buf.charAt(i)))
                return false;
        }

        return true;
    }

    /**
     * Tell if the string is whitespace.
     *
     * @param s String to check as XML whitespace.
     * @return True if characters in buffer are XML whitespace, false otherwise
     */
    public static boolean isWhiteSpace(String s) {

        if (null != s) {
            int n = s.length();

            for (int i = 0; i < n; i++) {
                if (!isWhiteSpace(s.charAt(i)))
                    return false;
            }
        }

        return true;
    }

}
